The purpose of the study is to adapt and test an evidence-based trauma treatment program for adolescent girls with histories of child maltreatment. The study adapts the CBITS (Cognitive Behavioral Intervention for Trauma in Schools) program for delivery within community-based settings for use with girls assessed and/or served by the child welfare system. The study utilizes a randomized clinical trial that evaluates the effectiveness of the adapted program entitled GAIN (Girls Aspiring toward Independence) compared with a usual care group. Primary outcomes of the intervention are mental health symptoms such as PTSD, depression, and internalizing and externalizing behaviors. Other outcomes include aggressive behaviors, revictimization, and aggression-related beliefs, self-efficacy, and behavioral intentions.